Articulated linkage connection for an excavating machine

ABSTRACT

An articulated connection for use in an excavating machine having a tractor frame and a digger frame. The articulated connection comprises a pair of link members each being pivotally connected at one end to the tractor frame and at their other ends to the digger frame to enable shifting movement of the tractor frame with respect to the digger frame for digging a curved trench.

United States Patent [151 3,704,534

Preu 1 Dec. 5, 1972 541 ARTICULATED LINKAGE 3,057,088 10/1962 George et a1. ..37/86 CONNECTION FOR AN EXCAVATING 3,232,586 2/1966 McClive ..280/460 R x MACHINE 3,571,956 3/1971 Heiberg.... ..172/677 x [72] Inventor: ans L. Preu Huron Ohi 2,729,469 1/1956 Wilson ..172/677 X [73] Assignee: American Hoist and Derrick Com- FOREIGN PATENTS APPLICATIONS pany, St. Paul, Minn. 207,810 2/1968 U.S.S.R. ..2l4/l38 R Filed g 12 1970 947,838 1/1964 Great Britain..... ..l72/677 [21] Appl. No.: 63,234 Primary Examiner-Robert E. Pulfrey Assistant Examiner-Clifford D. Crowder 52 US. Cl ..37/s3, 172/677, 280/460 A, Tea: and 53mm 280/494 57 ABSTRACT [51] Int. Cl. ..E02f 5/06 1 [53] Field f Sal-ch 214/13 230/4 0 492 9 An articulated connection for use in an excavating 37/86 172/677, 324, 699 machine having a tractor frame and a digger frame. The articulated connection comprises a pair of link 56] References Cited members each being pivotaliy connected at one end to the tractor frame and at their other ends to the digger UNITED STATES PATENTS frame to enable shifting movement of the tractor fam 'th ttthd' f f d 3,425,715 2/1969 Weitz ..280/460 A x 1 o gger F or 'ggmg a 3,398,471 8/1968 Brown ..37/86 3,484,843 .....280/494 X I 5 Claims, 5 Drawing Figures 12/1969 Martin PATENTEDBEB 51m 3.704.534

SHEEI10F2 INVENTOR F E. 2 HANS LPREU ATTORNE X5 ARTICULATED LINKAGE CONNECTION FOR AN EXCAVATING MACHINE BACKGROUND OF THE INVENTION This invention relates to excavating machines, and more particularly, to excavating machines capable of digging a curved trench.

Heretofore, digging a curved trench with conventional excavating machines has been extremely difficult and cumbersome. For example, excavating machines of the ladder-type construction have included a tractor unit to which a digging unit is pivotally connected being adapted to be pulled in trailing relation therebehind. Generally, these digging units have included endless digging elements capable of being pivotally raised and lowered in a vertical plane between a storage and digging position, respectively, but not capable of any relative sidewise movement with respect to the tractor unit. This arrangement has made it extremely difficult, if not impossible, to dig a curved trench in that any attempt to move the tractor unit laterally would usually result in binding contact of the digging element with the side walls of the already dug trench. Such contact has had a tendency to urge the tractor back to its initial aligned relation with the trench, and thus, prevent any turning movement thereof. Therefore, in order to cut a trench on a curve, it has been necessary to raise the digging element out of the trench and reposition the retractor unit in angular relation to the already excavated trench, and then lower the digging element into the trench to complete the excavating operation.

SUMMARY OF THE INVENTION The present invention contemplates providing an excavating machine which is capable of digging a trench on a curve, and more particularly, an articulated connection for use in an excavating machine having a tractor frame and a digger frame capable of independent angular movement with respect to one another. The articulated connection comprises a pair of link members each being pivotally connected at one end to the tractor frame and at their other ends to the digger frame to enable sidewise movement of the tractor frame with respect to the digger frame. A pair of pivotal connections are connected at spaced points to said tractor frame having generally vertically-oriented pivotal axes thereof to enable angular rotation of the link members in a generally horizontal plane. A pair of universal-like pivotal connections are connected at spaced points to the digger frame having both generally verticallyoriented and generally horizontally-oriented pivotal axes. Each of the universal-like connections includes a self-aligning assembly and a rotatable member is journaled in and couples the respective self-aligning assemblies together to maintain their vertical pivotal axes in generally stationary relation with respect to one another. The rotatable member supports the digger frame thereon being rotatable about a generally central axis. A fluid actuating means is operably connected between the tractor frame and the digger frame for rotating the digger frame in a generally vertical plane between a raised storage position and a lowered digging position upon rotation of the rotatable member.

By this arrangement, the tractor frame may be turned while the digger frame remains in a stationary position thus, preventing the digging element carried by the digger frame from being swung into binding contact with the side wall of the already excavated trench.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the articulated connection of the present invention adapted for use with an excavating machine;

FIG. 2 is a diagrammatic illustration, in top plan, of the articulated connection shown in FIG. 1;

FIG. 3 is a fragmentary, top plan view of the articulated connection shown in FIG. 1;

FIG. 4 is a side elevation view of the articulated connection of the present invention as viewed from the bottom of FIG. 3; and

FIG. 5 is an enlarged, fragmentary, partially in sec tion view of one of the link members illustrated in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now again to the drawings, the articulated connection of the present invention is illustrated in FIG. 1, generally at 2, and is shown as coupling a tractor frame 4 to the digger frame 6 of an excavating machine. Conventionally, the digger frame 6 is mounted adjacent the rearend of the tractor frame 4 being adapted to be pulled in trailing relation therebehind. The digger frame 6 supports an endless digging element 7 to perform the digging operation. Generally, the digger frame 6 is mounted on the tractor frame for pivotal movement in a generally vertical plane between a raised storage position and a lowered digging position. A fluid actuating means 8 is shown as being operably connected between the tractor frame 4 and the digger frame 6 for selectively raising and lowering the digger frame 6. As shown, a pair of oppositely disposed link members 10 and 12 are each pivotally connected at one end to the tractor frame 4 and at their opposite end to the digger frame 6 to enable sidewise movement of the tractor frame 4 with respect to the digger frame 6 so that the tractor may move independently of the digger frame when attempting to dig a curved trench.

Referring now to FIG. 3, in the form shown, the tractor frame 4 is provided with a pair of spaced, laterally extending support arms 14 and 15 which project outwardly and rearwardly from the tractor frame 4 in a direction toward the digger frame 6. Elongated pins 16 and 17 are supported adjacent the outer ends of the arms 14 and 15, respectively, being secured in position thereon by locking clips 20 and 21, respectively. Referring to FIG. 4, the pins 16 and 17 have their central axes 18 and 19 extending in a generally verticallyoriented direction. As shown, each of the pins 16 and 17 may be provided with recesses, such as at 22, adjacent the upper end thereof being adapted to receive one end of a respective one of the holding clips 20 and 21 in locking engagement therein to prevent axial movement of the pins when in the mounted position.

As each of the link members 10 and 12 is of essentially the same general construction, only one, such as 10, will be described in detail with like parts of the other link member 12 being designated by like numerals when necessary. Referring now to FIG. 5, the link member 10 is shown as being generally triangularshaped in configuration having a body 24 adapted at one end, such as the forward end, for pivotal connection to the outer end of the support arm 14, and at its other end, such as the rearward end, for pivotal connection to the digger frame 6. As shown, the body 24 includes an elongated, sleeve-like mounting member 25 supported adjacent the forward end thereof, such as by welding or the like, being adapted to receive the pin 17 axially therethrough to form a hinge-like connection. By this arrangement, the link member may pivot in a generally horizontal plane about the central axis 19 of the pin 17.

Adjacent the opposite or rearward end of the body 24, a self-aligning assembly is provided which includes a spherical bushing 26 having a shaft 28 journaled therein for rotation about its generally horizontallyoriented central axis 27. The bushing 26 may be of any conventional design as well known in the art to enable universal pivotal movement of the link member 10 with respect to the central axis 27 of the shaft 28. For example, the the rear end of the link member 10 may pivot about a generally vertically-oriented pivotal axis 23 of the bushing 26 while enabling the shaft to rotate within the bushing about its central axis 27.

Referring also to FIG. 3, each of the self-aligning bushings 26 are shown as having a movable inner sleeve 33 which is mounted within a stationary split sleeve 34 and being capable of rotation about multiple axes, such as 23 and 27. As shown, the split sleeve 34 is secured to the rear end of the links 10 and 12, such as by welding or the like. The movable inner sleeve 33 may be seucred in position within the split sleeve 34 in any suitable manner, such as by snap ring 35 or the like, and the shaft 28 may be secured to the sleeve 33 by a worker and nut 30 and 32, respectively. By this arrangement, the shaft 28 couples the rear ends of the link members 10 and 12 together, and thus, the vertical pivotal axes 23 and 29 of the bushings 26 carried by the links 10 and 12, respectively, are maintained in predetermined, fixed spaced relation with respect to one another.

The digger frame 6 is shown as being physically connected for pivotal movement with the shaft 28 to move the digger frame in a generally vertical plane between a raised storage position and a lowered digging position. Referring also to FIG. 4, the digger frame 6 is provided with a yoke-like extension 37 which projects forwardly toward the tractor frame 4 being adapted for connection to a fluid actuated motor 38. The fluid actuated motor 38 includes a fluid cylinder 39 having an extensible piston rod 41 mounted for reciprocating movement therein. The piston rod 41 includes a lug 42 adjacent its outer end adapted for connection to the extension 37 by a suitable fastener, such as a pin 43 or the like. The end of the fluid cylinder 39 remote from the piston rod 41 includes a lug 44 which may be pivotally connected to the tractor frame in any suitable manner, such as by a pin 45, to enable universal pivotal movement of the fluid cylinder with respect to the tractor frame and digger frame. The fluid cylinder 39 may be of the double-acting type including inlet/outlet openings, as at 45, adjacent the opposite ends thereof for connection to a suitable source of pressurized fluid. A control valve 46 may be operably connected between the source of pressurized fluid and the fluid cylinder 39 to selectively impart reciprocating movement to the piston rod 41. and thus, pivotal movement to the digger frame 6 for raising and lowering the same between the storage and digging positions.

Referring now to FIG. 5, the respective outer ends of each of the arms 14 and 15 may be provided with an abutment plate, such as at 47, being adapted for abutting and coacting engagement with the confronting forward ends'of the associated link members 10 and 12, respectively, to limit the pivotal movement thereof. Preferably, the forward ends of the link members 10 and 12 may be provided with abutment pads, such as at 49, which are spaced a predetermined distance from the respective plates 47 to limit the angular rotational movement of the link members 10 and 12 about their respective vertical pivotal axes, such as indicated by the angle a in FIG. 5.

As shown, in FIG. 2, the vertical pivotal axes 18, 19, 23 and 29 together define a trapezoid, when viewed in top plan, to achieve maximum shifting movement of the tractor frame with respect to the digger frame. For example, when the tractor frame 4 (indicated by the solid line 4) is in linear alignment with the digger frame (indicated by the solid line 6), the transverse distance between the pivotal axes 18 and 19 of the pivot pin 16 and 17, respectively, is less than the transverse distance between the vertical pivotal axes 23 and 29 of the spherical bushings 26 carried by the arms 14 and 15, respectively. As can be seen, when the pivotal axes 18 and 19 are positioned inwardly from the pivotal axes 23 and 29 in the normally aligned position of the tractor frame 4 with respect to the digger frame 6, the pivotal axis 19 adjacent the end of the arm 15 is free to pivot clockwise about and outwardly with respect to the pivotal axis 29 upon clockwise rotation of the pivotal axis 18 about and inwardly with respect to the pivotal axis 23. Thus, as the arm 14 moves rearwardly toward the digger frame the arm 15 will move forwardly away from the digger frame enabling the tractor frame to turn at a relatively sharp angle with respect to the digger frame than could be achieved should the axes I8 and 19 be spaced apart a distance substantially equal to the spacing between the axes 23 and 29. Preferably, and referring now only to the link 10, the pivotal axis 18 may be offset inwardly with respect to the vertical axis 23 by an angle b which is defined on one side by a line 57 extending through the vertical axes 18 and 23 and on the other side by a line 58 extending through the vertical pivotal axis 23 in a direction generally parallel to the direction of digging movement of the excavating machine when the tractor frame 4 is linearly aligned with the digger frame 6, as indicated by the arrow 59.

OPERATION Normally, prior to the commencing of a digging operation, the digger frame 6 is in a raised storage position and in generally linearly aligned relation with the tractor frame 4. If, for example, it is desired to dig a trench having a straight run, then a curved run and then a final straight run, the fluid motor 39 is actuated to lower the digging frame, and thus, the digging element I into engagement with the ground. Assuming the digging element has been actuated, it is continually lowered until the proper depth for the trench has been reached. At this time, the tractor frame 4 is moved forwardly, such as indicated by the arrow 59 (FIG. 2) and the digger frame 6 is pulled in trailing relation therebehind to dig the straight run. When it is desired to dig the curved run, the operator of the excavating machine simply turns the tractor frame 4 in the desired direction, such as to the left, as indicated by the dotted lines 62 in FIG. 2. When this occurs, the support arm 14 will move inwardly, as indicated by the arrow 54,

and rearwardly, as indicated by the arrow '52, in a l direction toward the digger frame 6 while the arm 15 will be moved outwardly and forwardly away from the digger frame 6 thus causing the tractor frame 4 to be pivoted about an axis, such as at 64, while the digger frame 6 remains in a relatively aligned relation with respect to the original direction of digging movement, as indicated by the arrow 59. Therefore, the trailing end of the diggine element, as at 72, will not be pivoted sideways across the previously dug trench into binding engagement with the side wall thereof. When necessary, the digger frame 6 may be raised out of the trench when in the pivoted position with respect to the tractor frame 4, as indicated by the dotted lines 62 in FIG. 2. As can be seen, the operator need not realign the tractor frame 4 with the digger frame 6, but rather may actuate the fluid motor 39 to cause the digger frame 6 to be pivoted upwardly about the central axis of the shaft 28 to the raised storage position. To complete the digging operation, the operator may then lower the digging unit 6 back into the trench and finish the curved run. Upon completion of the curved run, the operator may then turn the tractor frame 4 to linearly realign the digger frame 6 therewith causing the arm 14 to be pivoted outwardly and forwardly away from the digger frame 6 while the arm 15 is pivoted inwardly and rearwardly toward the digger frame 6. The fluid motor 39 may then be selectively actuated to raise the digger frame upwardly out of the trench to the reaised storage position, thus completing the digging operation.

lclaim:

1. In an excavating machine of the type including a tractor frame anda digger frame supported by the tractor frame for movement in a generally vertical plane between a raised nondigging position and a lowered digging position,

an articulated support assembly supported by said tractor frame to enable lateral shifting movement of said digger frame relative to said tractor frame comprising,

a pair of link members mounted on said tractor frame and adapted for supporting said digger frame,

a rotatable support member for supporting said digger frame for movement relative to said tractor frame,

said support member includes a generally horizontaloriented axis of rotation to enable pivotal movement of said digger frame in said generally vertical plane,

said link members each includes one pivotal axis connection at one end for pivotally connecting said link member to said tractor frame and another pivotal axis connection at the opposite end for pivotal connection to said support member,

said one pivotal axis connection comprising a hinge construction including a unitary, generally vertically-oriented pivotal axis to enable pivotal movement of said link members in a generally horizontal plane and prevent movement in a generally vertical plane to provide a support for said digging unit, said support member having one end journalled for rotation in one of said link members and its opposite end journalled for rotation in the other of said link members, said other pivotal axis connections each include at least a generally vertically-oriented pivotal axis to enable pivotal movement of said link members in a generally horizontal plane and relative to said sup-' port member while enabling rotation of said support member about its rotational axis, the spacing between the pivotal axes of said one pivotal connection adjacent said tractor frame is different than the spacing between the pivotal axes of said other pivotal connections adjacent said support member to enable abrupt movement of said tractor frame with respect to said digger frame upon turning movement of said tractor frame, and selectively actuable means pivotally connected between said tractor frame and said digger frame for moving said digger frame between said raised non-digging position and said lowered digging position and enable said digger frame to move relative to said tractor frame upon turning movement of said tractor frame. 2. In an excavating machine in accordance with claim 1, wherein said selectively actuatable means includes an extensible fluid motor connected at one end to said digger frame and at its opposite end to said tractor frame, and said fluid motor including self-aligning elements connecting said fluid motor to said tractor and digger frames adjacent its opposite ends to enable universal pivotal movement of said fluid motor with respect to said tractor and digger frames. 3. In an excavating machine in accordance with claim 1, wherein each of said other pivotal axis connections includes a spherical bushing, and said support member comprises a shaft having its opposite ends joumaled for rotation in said bushings to enable rotational movement of said shaft during pivotal movement of said link members with respect thereto. 4. In an excavating machine in accordance with claim 1, wherein each of said link members includes an elongated sleeve-like mounting portion adapted for connection to said tractor frame, each of said one pivotal axis connections includes an elongated pin member which is supported on said tractor frame and extends axially through said mounting portion for connecting the associated link member to said tractor frame, and the central axis of each of said pin members is coincidental with a respective vertically-oriented pivotal axis of said one pivotal axis connections such that each of said link members is restricted to pivotal movement in a generally horizontal plane about the central axis of its associated pin. 

1. In an excavating machine of the type including a tractor frame and a digger frame supported by the tractor frame for movement in a generally vertical plane between a raised nondigging position and a lowered digging position, an articulated support assembly supported by said tractor frame to enable lateral shifting movement of said digger frame relative to said tractor frame comprising, a pair of link members mounted on said tractor frame and adapted for supporting said digger frame, a rotatable support member for supporting said digger frame for movement relative to said tractor frame, said support member includes a generally horizontal-oriented axis of rotation to enable pivotal movement of said digger frame in said generally vertical plane, said link members each includes one pivotal axis connection at one end for pivotally connecting said link member to said tractor frame and another pivotal axis connection at the opposite end for pivotal connection to said support member, said one pivotal axis connection comprising a hinge construction including a unitary, generally vertically-oriented pivotal axis to enable pivotal movement of said link members in a generally horizontal plane and prevent movement in a generally vertical plane to provide a support for said digging unit, said support member having one end journalled for rotation in one of said link members and its opposite end journalled for rotation in the other of said link members, said other pivotal axis connections each include at least a generally vertically-oriented pivotal axis to enable pivotal movement of said link members in a generally horizontal plane and relative to said support member while enabling rotation of said support member about its rotational axis, the spacing between the pivotal axes of said one pivotal connection adjacent said tractor frame is different than the spacing between the pivotal axes of said other pivotal connections adjacent said support member to enable abrupt movement of said tractor frame with respect to said digger frame upon turning movement of said tractor frame, and selectively actuable means pivotally connected between said tractor frame and said digger frame for moving said digger frame between said raised non-digging position and said lowered digging position and enable said digger frame to move relative to said tractor frame upon turning movement of said tractor frame.
 2. In an excavating machine in accordance with claim 1, wherein said selectively actuatable means includes an extensible fluid motor connected at one end to said digger frame and at its opposite end to said tractor frame, and said fluid motor including self-aligning elements connecting said fluid motor to said tractor and digger frames adjacent its opposite ends to enable universal pivotal movement of said fluid motor with respect to said tractor and digger frames.
 3. In an excavating machine in accordance with claim 1, wherein each of said other pivotal axis connections includes a spherical bushing, and said support member comprises a shaft having its opposite ends journaled for rotation in said bushings to enable rotational movement of said shaft during pivotal movement of said link members with respect thereto.
 4. In an excavating machine in accordance with claim 1, wherein each of said link members includes an elongated sleeve-like mounting portion adapted for connection to said tractor frame, each of said one pivotal axis connections includes an elongated pin member which is supported on said tractor frame and extends axially thrOugh said mounting portion for connecting the associated link member to said tractor frame, and the central axis of each of said pin members is coincidental with a respective vertically-oriented pivotal axis of said one pivotal axis connections such that each of said link members is restricted to pivotal movement in a generally horizontal plane about the central axis of its associated pin.
 5. In an excavating machine in accordance with claim 1, wherein the spacing between the pivotal axes of said one pivotal axis connection is closer than the spacing between the pivotal axes of said other pivotal axis connections. 